Sleep is an essential component of optimal physiological and psychological functioning in humans. However, numerous studies have identified sleep deficits in patients within the critical care setting. Sleep deprivation has been shown to cause adverse effects including cardiovascular, respiratory, and endocrine variations, and altered psychological functioning such as cognitive dysfunction, decreased concentration, mood variability, and delirium. The critical care environment often contains stimuli that may be a causative factor in sleep alterations such as sleep deprivation, fragmentation or alterations in sleeping patterns. These environmental stimuli include noise, light, pain, discomfort, nursing care activities, medications, psychological stressors and underlying disease and have the capability to severely impact the quantity and quality of sleep in critically ill patients. The integrated research review identifies correlations between environmental stressors and sleep alterations in critically ill patients. Outcomes of interventions including earplugs and eye masks, behavior modification, complementary and alternative medicine and pharmacological considerations are examined. Additionally, implications for nursing education, research and practice are addressed. A current integrated research review incorporating nursing implications and alternative interventions could be significant to the provision of nursing care for the critically ill patient.